This invention relates to a finger mechanism of an industrial robot utilized in various fields of industry.
Such robot is usually used to transport an article from one point to the other. The robot to which the invention is applicable is used where the end point of the article is definite. For example, the robot is used to transport a workpiece to a chuck mounted on the head stock of a lathe and then to secure the workpiece by the chuck. When these operations are performed manually, the operator usually moves the workpiece to substantially the center of the chuck, then closer to the center of the chuck by moving the pawls and finally snugly abuts the workpiece to the bottom of the chuck. If such operations are to be performed by a robot, it is necessary to construct the robot such that the workpiece securely held by the fingers of the robot is brought close to the chuck by moving the arm of the robot which carries the fingers along a prescribed path, and then secure the workpiece to the chuck by moving the pawls thereof. If the workpiece is not correctly held by the fingers, the workpiece would be inclined with respect to a reference surface of the chuck or would become eccentric with respect to the chuck when the workpiece is transported to the chuck by the robot. If the workpiece were fastened to the chuck without regarding such inclined or eccentric condition, the fingers of the robot and the arm carrying the fingers will be subjected to an abnormal force thus damaging the robot. Further, if the workpiece were secured to the chuck and worked under such inclined or eccentric condition, the accuracy of the machining would be impaired.